| 摘要 |
PURPOSE:To accurately control toner concentration to the best value by confirming that a developer is not one-sided and then controlling normal toner concentration. CONSTITUTION:An end detecting means 9 detects the end of the operation of a developing unit 2 and the output of the end detecting means 9 and the output of a toner concentration sensor 5 which detects the toner concentration of the developer 3 in the developing unit are inputted to a storage means 10, thereby storing the output of the toner concentration sensor 5 at the end of the operation of the developing unit 2. A comparative judging means 11 compares the toner concentration output value at the end of the final (last) operation of the developing unit 2 stored in the storage means 10 with the output value of the toner concentration sensor 5 at the restart of the developing unit 2 to judge whether or not they are in specific relation, and a toner supply control means 12 controls a sensor supplier 13 according to the output of the comparative judging means 11. Consequently, the toner concentration is controlled to the best value. |
